Minority-spin band parameters in a NiMnSb thin film determined by spectral conductivity
| Autor: | Grigorescu, C. E. A., Trodahl, H. J., Strickland, N. M., Bittar, A., Manea, S. A., Giapintzakis, John, Monnereau, O., Notonier, R., Kennedy, V. J. |
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| Přispěvatelé: | Giapintzakis, John [0000-0002-7277-2662] |
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Materials science
Thin films General Physics and Astronomy Pulsed laser deposition Optical conductivity Absorption Half metals Condensed Matter::Materials Science symbols.namesake Nickel compounds Thin film Spin valence Electronic band structure Low temperature effects Condensed matter physics Fermi level Fermi energy Band structure Spectral conductivity Conduction bands Absorption edge symbols Condensed Matter::Strongly Correlated Electrons Half-metal |
| Zdroj: | Journal of Applied Physics |
| Popis: | NiMnSb is expected to be a ferromagnetic half metal, an expectation that is based in part on band structure calculations. Here we report optical conductivity studies of the band structure for a film prepared by pulsed laser deposition onto a Si substrate held at a relatively low temperature as is required for some device applications - films which are susceptible to site disorder associated with the vacant site in this half-Heusler compound. We demonstrate that the direct interband transitions are essentially unshifted in comparison with bulk material, though they are somewhat broadened. Below the direct-transition absorption edge we report the presence of indirect spin-reversing transitions between the Fermi energy (Ef) and the extrema of the minority-spin valence and conduction bands, providing a measure of the band edge energies. Both of these edges appear closer to Ef than is seen in well-ordered bulk NiMnSb, with the conduction-band minimum showing weight at only 200 cm-1 above Ef, close enough to have substantial occupation at ambient temperature. © 2004 American Institute of Physics. 96 6421 6424 6421-6424 |
| Databáze: | OpenAIRE |
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